1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly, to a memory card used in a mobile product and a method of fabricating the memory card.
2. Description of the Related Art
With the recent development of mobile products, applications of memory devices have been expanded. In particular, memory cards are expected to be greatly developed and to be given a great deal of weight on new field of semiconductor industry. Institutional safeties have been provided to protect the copyright of software with the wide-range popularization and development of the Internet. Also, several types of memory cards have been developed so as to complement the security of the memory cards.
Several types of compact, light memory cards are currently used as data storage of multimedia. For example, multimedia cards (MMCs) are provided. In the MMCs, memory devices and control devices are mounted on printed circuit boards (PCBs) and electrically connected to the PCBs using wire-bonding and protected using molding and capping, to thereby interface with a host device using a small number of signals.
FIG. 1 is a cross-sectional view of a conventional lid type memory card. Referring to FIG. 1, a semiconductor chip 14 is mounted in a predetermined position of a PCB 10 via an adhesive part 12, and an external terminal of the semiconductor chip 14 is electrically connected to a specific circuit terminal formed in the PCB 10 via bonding wires 18. A passive device 16 is mounted in a specific position of the PCB 10 according to the design. The semiconductor chip 14 is mounted as an electronic device on the PCB 10. However, package type electronic devices may be mounted on the PCB 10. Alternatively, the semiconductor chip 14 and the package type electronic devices may be mounted on the PCB 10.
After a bonding process performed on the semiconductor chip 14 is finished, the semiconductor chip 14 or the passive device 16 is sealed by a sealing part 20 formed of a sealing compound. Thereafter, the semiconductor chip 14 or the passive device 16 is cut as individual memory cards and then finally capped with a lid 22 so as to be physically and chemically protected from the external environment.
The above-described lid type memory card requires a large number of fabricating processes. Thus, the lid type memory card increases cost and is poor in terms of the high integration of electronic devices.
FIG. 2 is a cross-sectional view of a chip scale package (CSP) type memory card. Referring to FIG. 2, unlike the conventional lid type memory card shown in FIG. 1, the lid 22 that is a final protecting structure is not formed. Thus, compared to the conventional lid type memory card, a number of fabricating processes is reduced. As a result, cost is reduced. However, an electrostatic discharge characteristic is deteriorated. In other words, to form the PCB 10, a copper foil is compressed on a side or both sides of an insulating plate formed of a phenol resin, an epoxy resin, or the like. Next, a pattern is formed depending on a designed circuit, and an unnecessary portion is eroded to remove the copper foil. Hole or viaholes are formed to electrically connect lids of several types of electronic products mounted on the PCB 10, and plating wires are formed. Here, the plating wires are exposed to the side of the edge of the PCB 10. When moisture exists among the plating wires exposed to the external environment, the moisture forms an electric conductive line. Thus, static electricity is discharged among the plating wires. As a result, an ESD characteristic is deteriorated.